Add critical thinking and we’ll create a human but more expensive.

Well, you will have created an important part an /ideal/ human that will finally fulfill the mandate, and with more resources (read and digest many orders of magnitude more).

And for what the cost are concerned: to call it more expensive in instance terms I want to see the numbers first, and - have you consider the cost of "unfinished" humans as liabilities? The costs of fools, of crooks, of the vile, of conformists etc.?